"A great American success story." That's how Bob R. Simpson, chairman of the board and founder of XTO Energy Inc., described his company during today's congressional hearing--but the phrase also can be applied to the recent boom in U.S. natural gas production.

Testifying before the House Subcommittee on Energy and Environment, Simpson said advanced drilling technologies have led to a sharp increase in the production of natural gas from hard-rock formations such as the Barnett and Marcellus Shales, and gas producers "may have only scratched the surface."

Both Simpson and Rex Tillerson, chairman and CEO of ExxonMobil, said the United States now has about 100 years worth of natural gas at today's consumption rates.

Today's hearing was held to examine the proposed merger of XTO with ExxonMobil, but most of the discussion focused on hydraulic fracturing, the practice that creates tiny fissures in shale rock allowing natural gas to flow into the wellbore. Some members of Congress have questioned whether the federal government should enact new hydraulic-fracturing regulations to protect ground water.

"As Energy Secretary Stephen Chu said just last week, hydraulic fracturing is safe and lawmakers should be cautious in their efforts to restrict it," said Jack Gerard, API's president and CEO in a statement. "Hydraulic fracturing is a proven technology that has been used safely in this country for 60 years. It is crucial in the development of clean-burning natural gas needed to heat and cool homes, generate electricity, and create basic materials for fertilizers and plastics."

Simpson told lawmakers today that virtually every well drilled by his company uses hydraulic fracturing. Tillerson added there have been more than a million wells drilled using hydraulic fracturing in the United States, and not one has been documented as contaminating ground water. Furthermore, he said, "Without hydraulic fracturing, the gas locked in the shale rock stays locked."

Jack Gerard warned that new federal regulations could have dire economic consequences. "Unnecessary additional regulation of this practice would only kill jobs, threaten our economy and hamper our nation's energy security. Studies estimate up to 80 percent of natural gas wells drilled in the next decade will require hydraulic fracturing."

More information about hydraulic fracturing is available here.